Progressive Retinal Atrophy in Dogs

The retina at the back of the eye is where light signals are sent to the brain and translated into images. The cells that send these signals to the brain are called photoreceptors. Progressive retinal atrophy is a genetic condition where the photoreceptor cells gradually lose function or are defective at birth, resulting in vision loss.

Progressive retinal atrophy is a painless condition that does not affect the overall health or life expectancy. However, there are a variety of other medical conditions that also result in vision loss, and medical intervention is required to ensure proper diagnosis.

Progressive retinal atrophy can result in cataracts, an opacification of the lens inside the animal’s eye.

PRA is genetic, inherited from both parents. Breeding pairs who both carry the gene have a high probability of passing it to offspring. Genetic testing is available for breeding stock to aid in prevention of this disorder.

Susceptible breeds include Bedlington Terriers, Cavalier King Charles Spaniels, Labrador and Golden Retrievers, Rottweilers, American Cocker Spaniels, and English Springer Spaniels

Progressive retinal atrophy is an inherited condition most commonly diagnosed in purebred dogs. It comes in two different forms:

Developmental retinal atrophy results when the photoreceptors don’t develop properly. Symptoms present as early as the first weeks of life, and complete blindness occurs within a couple years.

Degenerative retinal atrophy is caused by the photoreceptors degenerating over time later in the dog’s life.

Early symptoms of retinal atrophy can be very difficult to spot. The eyes become more dilated as they try to take in more light, and there may be a shiny sheen visible through the pupils, but there are no obviously visible changes to mark the condition.

Vision loss may not be apparent at all in a familiar environment, as dogs do not rely on their vision as much as people do. It is most visible in unfamiliar areas, and is usually noted when the pet bumps into things, has difficulty navigating differing heights, and moves with obvious uncertainty.

Diagnostics to determine retinal atrophy include a maze test to assess vision loss, electroretinography, and an ophthalmic exam. Reference to an ophthalmologist is an option, however there is no treatment available for this condition.

There is no treatment or medication to reverse or improve the symptoms of PRA. Degeneration of the retina is not painful, so pain management or removal of the eye(s) is not required either.

Management of PRA becomes a matter of adapting to lack of vision. New commands to account for unseen terrain such as curbs or steps can help prevent the dog from becoming injured, as can installing barriers such as baby gates in the home. Keeping to familiar walking routes, and avoiding rearranging home furniture helps the animal navigate safely and with more confidence.

Progressive retinal atrophy has no cure and causes permanent blindness, however it does not have a negative impact on the dog’s overall health.

The gene responsible for retinal atrophy has been identified, and is most commonly inherited from both parents. There are testing programs available for breeding stock, so as to not pass the condition on to subsequent generations. The condition is not contagious.

Retinal atrophy is common in certain breeds of dogs.

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